Adding the display mask to the final RMS/MAX pressure profile plot

By following this thread(http://www.k-wave.org/forum/topic/getting-started-with-mrict-scans-intracranial-pressure-maps-skull-aberration?replies=5#post-6368) I managed to define a skull as heterogeneous density profile mask ran the simulation successfully. Problem is, the skull is not showing up at the final RMS and MAX pressure plots. I successfully put skull on the short video/animation during the simulation by setting the display mask to the skull, but stuck on doing that on the final plots.
What can I do to add the display mask on the final result plots?
Thank you!!
I attached that part of the code here:
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